The effect of concurrent infection with Trichinella spiralis on Hymenolepis microstoma in mice.

The intestinal changes brought about by rejection of Trichinella spiralis from mice were studied in relation to their effects on a concurrent infection with Hymenolepis microstoma, a cestode not normally rejected from mice. The rejection phase of T. spiralis was associated with a marked stunting of growth of H. microstoma given just before, during, or just after rejection of the nematode. The survival of H. microstoma was affected only when rejection of T. spiralis coincided with the intestinal phase of the cestode: if T. spiralis rejection was timed to occur after the scolex of the cestode had entered the bile duct there was no loss of H. microstoma. It is suggested that the adverse effects on growth and establishment of H. microstoma were due to the non-specific inflammatory component of the host's response to infection with T. spiralis.